Relay



March 22, 1938. G. c. ARMSTRONG RELAY Filed Nov. 21 1955 iz y. 2.

INVENTOR ATToRm WITNESSES:

Fatented Mar. 2'2, l fiti UNITED of Pennsylvania Application November fill, 1935, Serial No. 5 19, 365

id @lairns.

' This invention concerns a time-delay relay, in which the delay mechanism is operated by the action of alternating flux upon a rotatable body in an air gap of the magnetic circuit. A more detailed discussion of the principles acting in such an air gap will be found in my co-pending application, Serial No. 46,287, filed October 23,

It is an object of this invention to provide a less expensive and more positive action of the delay mechanism than is found in time-delay relays heretofore known.

It is a further object of my invention to provide a screw mechanismoperated by the fi in the air gap and acting to produce a thrust for controlling the delay mechanism.

Other objects of my invention and details of the structure will be apparent from the following description and the accompanying drawing, in which:

Figure 1 is an elevational view of the relay looking toward the side upon which the armature is pivoted;

Fig. 2 is a top plan view of the same relay;

Fig. 3 is a view looking toward the bottom of Fig. 1;

Fig. 4 is a circuit diagram illustrating the use of such a relay; and

Fig. 5 is a detail view in perspective of a portion of the relay.

The relay includes a magnetic circuit comprising a stationary part I and an armature 2. The circuit is equipped with a coil 3 intended to be energized by alternating current, and the armature is supplied with a shading coil 4 in order that it may respond effectively to the alternating current. The stationary part of the magnetic circuit is laminated and provided with brass side plates 5 and 5 having feet. On the upper side, the plate 5 is extended to form an angle member I0, which is integral with a stirrup II, in which a detent member I2 is mounted. The stationary portion I of the magnetic circuit comprises a portion 8 mounted on the base I and two portions 9 and 9 extending toward the armature.

The side members 5 and 5' are widened beyond the laminated structure to provide ears I3, in which is mounted a pivot bolt I4. The armature is mounted upon this pivot bolt by means of non-magnetic side members I5. The side members I5 are traversed by the pivot bolt I4, and on one side thereof are extended to form a tail piece whichin the open position of the armature stops against the stationary magnet member 9', and are spaced by a spacer I 6, which is (@i. ZiDiD -ilii) held by a shoulder rivet. On the other side of pivot bolt, laminations fill the space between the side members and they are secured by rivets. The armature laminations do not extend all the way to the pivot bolt, but as indicated at it, they stop short of the length of the arm of the side members. The portions of the side members which contact the laminations of the armature are equipped with flanges 20 and 2 i. Between the side members I15 is mounted a contact carrying member 2%. At the pivotal end, this contact carrying member is bifurcated'to provide a stirrup 26 which extends past the pivot pin. 94, and each bifurcation is perforated to afford a bearing on this pin.

Above the flange 2i the contact carrying member is perforated to provide room for a stud 2i which is headed below the flange, as shown at 28, and carries a spring 29 confined by collars and a cotter pin 30 which causes the spring 29 to exert a bias upon the member 25. A similar stud pierces the member I2 and the stirrup I l and is headed at 33. It bears a spring 31' confined between two collars and secured by a cotter pin 38 which biases the detent member I2 to the illustrated position. The member I2 is equipped with a laterally extending portion 40, which is perforated to afford passage to a rod 4 I This rod is preferably integral with a screw 43, and an abutment flange 44 is preferably integral with both. The screw 43 is equipped with a nut 45 and a jam nut cooperating therewith. In the illustrated position, the nut 45 bears against the side member 5' and limits movement of the screw 43 downward as seen in Fig. 1. The side member 5 upon the upper side of the laminations, as seen in Fig. 1, is provided with an ear 46 to provide this abutment! The screw 43 extends through .the air gap between the upstanding portion 9' of the magnetic circuit, and the lamination end I8 of the armature. The pole face I9, which isthe end of portion 9, extends from the lower edge 50 as shown in Fig. 3 to the upper edge 5 I. When the screw 43 extends through the air gap between the pole face I 9 and the pole face I8, it rests upon the pole face I9. This screw is biased toward the lefthand position, as shown in Fig. 2, by the spring 55. (See Fig. 5.) The spring is mounted on the foot 6 of the lower side member 5 as seen in Fig. 1 and is equipped with a laterally extending portion 56 shown in dotted lines in Fig. 1, which will engage the lower face of the member 9' of the magnetic circuit and so limit the movement of the spring. The spring 55 is equipped with a bearing block 60 (see Fig. 5), which is provided with threads to cooperate with the threads of the screw.

A spring BI is wound upon the upper end of the pivot bolt l4 and secured at its left-hand end, as shown in Fig. 1, in a groove in the head of the rivet I6. Its other end is hooked around the side member 5' and its action isto bias the armature 2 to open position. The armature 2 carries a cam member 62 secured to the underside of the flange 2| by means of a bolt 53. The end 54 of the cam member 62 is curved upwardly to contact the screw 43 when the armature 2 moves to open circuit position and push the screw 43 out of engagement with the block 60 on the spring 55, as subsequently described in detail.

The distal end of the contact carrying member 25 is curved to afford a contact 55. This cooperates with a stationary contact 86 mounted upon any suitable insulating support. The contact carrying member 25 at times carries current and it is desired to provide a connection for such current around the bearings on the pin I4 in order to avoid heating of said bearings. For this purpose a flexible conductor omitted in Fig. 2 is secured in the hole 61 upon the member 25 and under the head of pivot II or to any point electrically continuous with side member 5.

In the operation of the device, the coil 3 is energized with alternating current, which has the effect of attracting the armature 2 and of setting up an alternating flux between pole face I! and pole face I9. The screw 43 is thus subjected to an alternating magneto-motive force, and because of its own hysteresis, the polarities established therein have a somewhat diflerent phase from the polarities established upon the pole faces 19 and IS. The combined effect of this hysteresis, the action of the spring 55 and the alternating magneto-motive force in the gap |9--l8 causes the screw to rotate, clockwise as seen in Fig. 3. This action is further explained in my above mentioned copending application. When the screw rotates, there is coaction between the threads of the screw and the threads of the block 60 causing the screw to travel upward as seen in Fig. 1.

The attraction of the armature 2 causes it to move completely into contact with the portion 9 of the magnetic circuit, but the contact carrying member 25 will not at first travel as far as this. It will be arrested by contact between it and the distal end of the member l2. After this, there is relative movement between the contact carrying member 25 and the armature 2 causing a separation between them, best illustrated in Fig. 3. This relative movement compresses the spring 29, the stud 21 having been mfied by movement of the armature while the member 25 was stopped by detent I2.

As the screw 43 moves upward, the flange 44 comes into contact with the lateral projection upon the detent member l2 and presently moves the detent against the action of the spring 31 until the end of it ceases to contact the contact carrier 25. When this occurs, the contact carrier moves under the action of spring 29 and brings the contact 65 against the contact 55. This will not occur until some time after the coil 3 is first energized.

The length of this time is adjusted by adjusting the nut on the screw 43. If this is so adjusted that the screw 43 is originally in a higher position than that illustrated in Fig. 1, the disengagement between the detent i2 and the contact carrying member 25 will occur sooner. If itis adjusted so that it is lower than the illustrated position of Fig. 1, the disengagement will occur later. The length of the screw 43 is such that soon after the flange 44 engages the lateral projection 40, and the contacts have closed, the screw 43 will disengage the block 50. When this occurs, the spring 55 will cease to exert any bias upon the screw 43 and the rotation which resulted from the combined action of several causes, including this spring 55, as noted above, will cease. The screw, therefore, will cease to rotate. The spring 55, being now free from the screw 43, moves until the stop 56 hits against the member 8'. In the resulting position the spring and block hold the screw from retuming under gravity to the position of Fig. 1.

When the coil 3 is deenergized, the armature 2 is moved to open position by the action of the spring 5|. During this motion, the end 64 of the cam 52 engages the screw 43 and moves it upward as shown in Fig. 3, which is toward the left, as shown in Fig. 2. The spring 55 being now in the position in which the contact of stop 40 with member 5 placed it, the cam 62 does not release the screw 43 from resting upon the spring 55 until the cam has moved the screw beyond this position of the spring, that is, until the armature 2 has been moved by spring 6| nearly to its completely open position. The screw 43 will then fall under the action of gravity to the position illustrated in Fig. 1. Obviously, a bias other than gravity for returning the screw 43 may be provided and the relay may then be used in other than the position illustrated in Figs. 1 and 2.

An illustration of the use of this relay is shown in Fig. 4 which shows a three-phase supply circuit I0 for energizing a motor illustrated in a conventional way at H. A familiar form of switch is shown at 12, which is operated by the action of a push-button 13. When operated, it establishes a holding circuit for itself at 14, which may be opened by a push-button I5. When the motor is first started by pushing the button 13, its secondary circuit includes a resistor 16. The energizing coil 3 of a relay of the type described above is connected across a primary winding of the motor, which will cause the armature 2 to move to closed position, but the contacts 65 and 65 will not close until after the lapse of a predetermined time. At the end of this time, the pin 4| will have ascended so far that the abutment 44 will have moved the detent I2 to release position and then the spring 30 will cause the contacts 55 and 56 to close. When they close, the coil 11 will be energized, which will close the contacts that remove the resistance 15 from the secondary circuit of the motor.

Many variations in the mechanical details shown and described will occur to those skilled in the art, and I desire, therefore, that only such limitations shall be imposed on my invention as are indicated in the appended claims.

I claim as my invention:

1. In a time-delay relay, a magnetic circuit comprising a magnetizable structure and an armature movably related thereto, a contact-carrying structure yieldably constrained to move with said armature, a detent for said contact-carrying structure, means for energizing said magnetic circuit with alternating flux, said magnetic circuit having an air gap between said magnetizable structure and said armature, a magnetic body pivotally mounted within said air gap for movement therein, and a device operated upon the energization of said magnetic circuit and of Cir gym 1 for moving said detent to comprising a magnetizable structure and an armature movably related thereto, a contactcarrying structure yieldably constrained to move with said armature, a detent for said contact-carrying structure, means for energizing said magnetic circuit with alternating flux, said magnetic circuit having an air gap between said magnetizable structure and said armature, a magnetic body in said air gap, a spring biasing said body away from one face of said gap, whereby said body will rotate when the magnetic circuit is thus energized, means for obtaining a translatory movement from said rotation, and means operated in accordance with said translatory movement for moving said detent to release position.

3. In a time-delay relay, a magnetic circuit comprising a magnetizable structure and an armature movably related'thereto, a contact-carrying structure yieldably constrained to move with said armature, a detent for said contact-carrying structure, means for energizing said magnetic circuit with alternating fiuxfsaid magnetic circuit having an air gap between said magnetizable structure and said armature, a threaded body in said air gap, a spring biasing said body away from one face of said gap, whereby said body will rotate when the magnetic circuit is thus energized, said spring carrying threads cooperating with the threads of said body to cause translation thereof upon said rotation, and means actuated in accordance with said translation to move said detent to release position.

4:. In a time-delay mechanism, a magnetizable structure having an air gap, a member mounted to have motions of both rotation and translation in said air gap, means for energizing said magnetizable structure with alternating flux, a yieldable biasing means cooperating with said member to cause rotation and translation thereof when the magnetizable structure is energized,

and a thrust member controlled in accordance with the motion of translation of said firstnamed member.

5. In a time-delay relay, a contact controlling member, a detent normally preventing said member from moving completely to contact-closing position, screw-threaded means for moving said detent to inoperative position, and means for moving said contact-controlling member to contact-closing position, said two means having a common magnetic circuit.

6. In a time-delay relay, a contact-controlling member, a detent normally preventing said member from moving completely to contact-closing position, means for moving said detent to release position, and means for moving said contactcontrolling member to contact-closing position, said two means having a common magnetic circuit having two air gaps one of which is shortened to effect the movement of the contact-controlling member and the other is of a length which changes to a. less degree during the movement of the contact-controlling member, the means for moving the detent including a magnetic body in the last-mentioned air gap.

7. In a. time-delay mechanism, a magnetizable structure having a stationary and a movable structure and an air gap between them, a screwthreaded body in said gap-cooperating with one face thereof, a spring biasing said member away from the other face of said gap, a threaded bearing block. mounted on said spring and cooperating with the threads on said body, means for biasing said movable structure to a predetermined position, and means responsive to such biased movement of said movable structure for disengaging said screw-threaded body from said hearing block.

8. In a time-delay relay, a magnetic circuit comprising a magnetizable structure and an armature, an air gap between them, a magnetic screw-threaded member in said air gap, a springpressed threaded member biasing said magnetic member away from one face of said gap, and means carried by said armature and acting upon the deenergization of the magnetic circuit for moving said magnetic screw-threaded member beyond the range of movement of the springpressed threaded member, whereby upon said deenergization the magnetic screw-threaded member will be free to be moved by gravity.

9. In a time-delay relay, a magnetic circuit comprising a magnetizable structure and an armature, an air gap between them, a magnetic screw positioned in said air gap, means including a threaded pressure block and a spring for causing it to bias the screw away from one face of the air gap for causing the screw to be moved longitudinally against a bias, a spring for moving the armature to open position upon deenergization or the magnetic circuit, and means 210- tuated by said movement of the armature for disengaging said screw from said pressure block, whereby said screw is then free to move in response to its bias.

10. In a time-delay relay, a magnetic circuit comprising a magnetizable structure and an armature pivotally connected together, means for energizing said magnetic circuit with alternating flux, said magnetic circuit having a gap adjacent the pivot point of the armature, a magnetic screw in said gap in contact with one face thereof, a spring-pressed bearing block biasing said screw away from the other face of said gap, a stop for limiting the movement of said bearing block, a thread on said block cooperating with the threads of said screw when in engagement, an adjustable stop on said screw limiting its movement in the direction opposite to the action of said threads, a thrust member comprising an abutment on said screw, a contact carrying member mounted on said armature, a spring yieldably constraining said contact carrying member to move with said arma ture, a spring biasing said armature in opposition to the flux, a cam carried by said armature and acting upon said screw to move it out of engagement with said bearing member upon movement or" said armature in response to said bias, and a detent preventing said contact carrying member from completely following the movement of the armature, sa d thrust member acting upon said detent when the screw has traveled a distance determined by said stop on the screw to move the detent to inoperative position.

GEORGE C. ARMSTRONG. 

